Tetsuji Imanaka
Research Reactor Institute, Kyoto University

Abstract

As one of the first steps to start reevaluating radiological consequences from the so-called "black rain" after the Hiroshima bombing, radiation survey activities soon after the bombing by both Japanese scientists and the US military were reviewed. Although intensive studies were conducted to measure residual radiation in the city area of Hiroshima, radiation survey in the mountainous area where strong black rain was reported was found to be sparse and insufficient.